1. Field of the Invention
The present invention relates generally to methods and systems for segmenting digitally scanned documents into two or more planes, and more particularly to methods and systems for segmenting digitally scanned documents into planes suitable for a Multiple Raster Content (MRC) representation of documents.
2. Description of Related Art
The MRC representation of documents is versatile. It provides the ability to represent color images and either color or monochrome text. The MRC representation enables the use of multiple “planes” for the purpose of representing the content of documents. The MRC representation is becoming increasingly important in the marketplace. It has been already established as the main color-fax standard.
In an MRC representation, an image is represented by more than one image plane. The main advantage of the MRC representation of documents is to provide an efficient way to store, transmit, and manipulate large digital color documents. The method exploits the properties of the human vision system, where the ability to distinguish small color variations is greatly reduced in the presence of high-contrast edges. The edge information is normally separated from the smoothly varying color information, and encoded (possibly at higher resolution than 1 bit per pixel) in one of the planes, called the Selector plane. Following a careful separation, the various planes could be independently compressed using standard compression schemes (such as JPEG and G4) with good compression and high quality at the same time.
There is a need for a method and a system for efficiently separating an image into a set of planes, such that the advantages of the MRC representation can be fully exploited.